Ptp => No support for HW time stamping

Linux Kernel
1

hi

context:

  • board: Altera Cyclone V SoC Board
  • kernel: Linux buildroot 5.4.45
  • dts: socfpga_cyclone5_socdk

i try to use ptp, but i get this error at boot:
socfpga-dwmac ff702000.ethernet eth0: No support for HW time stamping

and when i start ptp4l:

ptp4l -i eth0 -s -m

ptp4l[268396.328]: selected /dev/ptp0 as PTP clock
[268396.346140] socfpga-dwmac ff702000.ethernet eth0: No support for HW time stamping
ptp4l[268396.347]: driver rejected most general [HWTSTAMP filter268396.353824] socfpga-dwmac ff702000.ethernet eth0: No support for HW time stamping

ptp4l[268396.360]: ioctl SIOCSHWTSTAMP failed: Operation not supported
ptp4l[268396.361]: port 1: INITIALIZING to FAULTY on FAULT_DETECTED (FT_UNSPECIFIED)
ptp4l[268396.361]: port 0: INITIALIZING to LISTENING on INIT_COMPLETE

cat /sys/kernel/debug/stmmaceth/eth0/dma_cap

==============================
DMA HW features

    10/100 Mbps: Y
    1000 Mbps: Y
    Half duplex: Y
    Hash Filter: Y
    Multiple MAC address registers: Y
    PCS (TBI/SGMII/RTBI PHY interfaces): N
    SMA (MDIO) Interface: Y
PMT Remote wake up: N
    PMT Magic Frame: N
    RMON module: Y
    IEEE 1588-2002 Time Stamp: N
    IEEE 1588-2008 Advanced Time Stamp: Y
    802.3az - Energy-Efficient Ethernet (EEE): Y
    AV features: N
    Checksum Offload in TX: Y
    IP Checksum Offload (type1) in RX: N
    IP Checksum Offload (type2) in RX: Y
    RXFIFO > 2048bytes: Y
    Number of Additional RX channel: 0
    Number of Additional TX channel: 0
    Enhanced descriptors: Y

any idea ? thanks a lot